Continuously operating centrifuge



Sept. 2, 1941.

A. E. SORENSO'N CONTINUOUSLY OPERATING CENTRIFUGE Filed Feb. 4, 1939 2 Sheets-Sheet 1 .lllll 1 I ATTORNEY p 1941' A. E. somzwsom 2,254,455

GONTINUOUSLY OPERATING CENTRIFUGE Filed Feb. 4, 1939 2 Sheets-Sheet 2 FIE-i Patented Sept. 2, 1941 V UNITED STATES PATENT OFFICE v 2,254,455, i j

coNTiNUoUsLY orEe-e'rmGfcENTRIFUcE I I Arthur E. Screnson, Crockett, Calif. Application February 4, 1939, Serial'No. 254,627

7 Claims. (oi. 210-68) Y My present invention relates to centrifugal filtering and/or separating devices and more particularly to a new and improved form of centrifugal machine in which the filtering and/or separating operation is carried out in a continuous manner. n V 7 An object'of the invention is to provide a new, novel and practical centrifugal device for filtering or separating solid matter, insoluble or Soluble,

from'fiuids or liquidsof different specific gravity IQ ceptacle, means for reciprocating said receptacle while in rotation and which can be adjusted to reciprocate the receptacle at any predetermined frequency independently of its rotative speed.

Another object of the invention is to provide a continuously operating centrifugal separating machine in which .there is provided a filtering Q a device constructed in accordance with the inzone, a purging zone and a drying zone through which the material under treatment will progress in a continuous manner and one in which the filtrate will be collected and separated from the purging fluid.

Another object of the invention is to provide in combination with a continuously operating centrifugal machine "of the character describedfin which the solids are discharged at the rim of a centrifugally operating receptacle, means for collecting the solids and directing them into a desired receptacle or channel. At the present'time themostsucces'sfully operating centrifugals in use for separating molasses from sugar solutions and/or purging concentrated granular sugar solutions consists of a centrifugally operating receptacle having a perforate cylin- 15; ceptacle.

the solids are subjected to a spray of wash water fora predetermined period and then allowed to spin for an additional predetermined time for the purpose of discharging'the wash water and partially drying the crystallized solids. After this operation the centrifugal receptacle is slowed down and a stationary plow is swung into position against the side wall of the receptacleto dislodge the accumulated solids which are then dis- ;charged through an opening at the bottom of the receptacle. With this type of apparatus it will be readily seen that the operation thereof consumes considerable time due to the necessity for a periodic charging and discharging of the rev It is; therefore, a further object of the invention to provide a centrifugally operating machine which will overcome this difficulty. and which when once put into operation can be operated infa continuous manner.

; Other objects" and" advantages will be in part evident to those skilled in the art and in part pointed out in the following description, taken in connection. with" the accompanying drawings, wherein there is shown by way of illustration and 5 ;not of limitation apreferred embodiment of the invention.

Injthe drawings,.gwherein'like numerals refer to like parts throughout the several views;

Figurel is a vertical sectional View through vention;

Figure-2 is a side elevation of a portion of the apparatus illustrated in Figure l of the drawings, Figure 3 is a fragmentary plan view partially 3% in sectiontaken along line III-III of Figure 1 looking in direction of arrows,

Figure lis' a" fragmentary sectional view showing the details of .the centrifugally operating receptacle;

Q Figure 5 is an enlarged sectional View of a detail of the receptacle as illustrated in Figure 4,

and i Figure 6 is a plan view of a further detail of the receptacle illustrated in Figure 4.

Before proceeding with a detailed description of the'apparatus chosen for illustration it may be said that the present invention contemplates a centrifugal machine having a receptacle with a perforate outwardlyfiaring or frusto-conical side Q=yva1l over which the material subject to separation is advanced in a continuous manner through what may be termed three zones of treatment; namely,- a zone A, near the bottom of the receptacle where the thick syrup and/or raw ;:filtrate is separated fromthe material undergoing treatment; a zone B, where wash water is able speed through a speed reducing device 30 applied to the rotating mass for purging the 1 invention, therefore, in addition tothe centrifu gal separation of the liquids and solidsfalso conof the type commonly referred to in the trade as a Reeves variable transmission. For the purpose of this description it will be suflicient to state that this Reeves transmission comprises two sets of adjustably mounted and opposed cone pulley surfaces 3| and 32 over which a power transmitting belt 33 passes. With this type of transmission it is possible to vary the relative speeds of the driving and driven shafts to produce any desired ratioof reduction by simultaneously enlarging the belt contacting diameter of the driv ing shaft while reducing the belt contacting diameter of the driven shaft or vice versa, de-

pending uponwhethe'r an increase or a decrease in the speed of the driven shaft is desired. These drives are made for both manual and automatic templates a reciprocation of the centrifugal remgs is of the automatic type and for controlling ceptacle at a frequency which will create and maintain a jogging movement of the material undergoing treatment along the filter. forming perforate outwardly flaring wall of the receptacle. The frequency of the reciprocationandthe mag-. nitude thereof is so chosen withvrespeot'to the particular material under treatment that the movement of the material through the machine 7 will be properly timed -to effect the desired filtra tion thereof. 1

In addition to the novel construction and ope eration of the machine',.as broadly set forth above,.the invention also contemplates an association with thecentrifugally operating receptacle of a plurality of separating conduits by means of which the filtrate, the wash water. or diluted filtrate, and the recovered solids are each directed into separate channels for future treatments.

Reference is now made to the drawings for a detailed description of apparatus embodying the present invention. As illustrated in Figure 1, the centrifugal receptacle, designated generally by the numeral [0, is mounted upon' the upper end of a vertically disposed shaft I I that is adapted to be driven at a high rotative speed by means of a motor [2. As here shown, the motor I2 is connected in driving relation with the shaft II by means of a belt l3 which passe's'over pulleys E4 and [5 carried respectively by the shaft H.

The clevis-like member I8 has a short'horizontal shaft l9 and connected between this horizontal shaft [9 and an offset or crank forming portion 20 of a horizontally disposed shaft 2| thereis'a pitman or connecting rod 22. 'The shaft 2| is journaled in a horizontal position upon bearings 23 that are carried by a foundation plate 24 arranged therebeneath. In order to counterbalance the weight of the vertically moving partsassociated with the shaft II, when in operation the shaft 2| also carries two counterbalancing fly wheels 25, one of which is located at each side of the crank forming portion 20 thereof. The shaft 2| with its crank forming portion 20 and the counterbalancing fly wheels 25 is adapted to be driven by a second motor 26. For this purpose the shaft 2! is provided with a pulley 21 over which a belt 28 passes. The belt 28 connects with a pulley 29 which is driven at a Varito hereinabove.

adjustments. The device illustrated in the drawthe adjustments thereof there is shown a small motor 34. At this point it should be noted that the stub shaft I1 is journaled in the yoke-like member 16 by means of roller bearings 35 which provide what might be termed a reciprocating step'bearing at the lower end of the shaft II. Surrounding the shaft I l and mounted in axially spaced relation there are two bearings 36 and 31 that: are slidably mounted between guides 38 and 38 which are carried by oppositely arranged stationary pedestals 40. As shown, the pedestals 40 and the driving motor {2 are mounted upon a structural iron support which is suspended beneath a floor 42 of a building by means of struts 43 and the horizontally disposed shaft 2| is shown as mounted upon a'foundation 44 which may be the next lower floor of a refinery building. With this arrangement it will be seen thatthe centrifugal receptacle ID will be located with respect to the floor 42 so that an attendant can observe and take care of the operation of the machine in a convenient manner. For this purpose the invention contemplates that when installed each machine will have arranged adjacent thereto a suitable control board which will carry suitable speed indicating devices and switches duit 45 through which the massecuite or other.

material is introduced into the receptacle ID.

.This feeding conduit 45 may be of any suitable size. In practice it is contemplated that it will connect with a hopper (not' shown) from which the material will'fiow by gravity. The feeding conduit 45 is supported upon a structural iron frame'46 and at its lower end it carries an internal spider 41 having a central opening through which a centering stud 48 carried by the shaft ll extends. This providesfor an exact centering of the feeding conduit 45 with respect to the centrifugal receptacle 10 during its operation. Arranged around the feeding conduit 45 and extending'into the receptacle ID to a'point intermediate the top and bottom thereof there is one or morewash water dispensing spray nozzles 49. As illustrated, the spray nozzles are located substantially midway between the top and bottom of the receptacle If! so that when in operation the perforate side wall of the receptacle III will be divided into the three distinct zones referred As indicated in this figure of the drawings, zone A, which comprises the filtering zone extends from the bottom of the receptacle II] to a point along the wall thereof 'where the wash water leaves thesame. The zone B covers that portion of the perforate wall of the receptacle I9 through which themajor portion of the wash wateris discharged therefrom, while the zone C comprisesthe'remaining portion of the perforate wall of thereceptacle 19. In connection with the washing aspect of this invention it should be stated that while I have shown two spray nozzles 49 arranged one on each side of the material feeding conduit 45, it is contemplated that even a larger number of these spray nozzles 49 may be used. It is also conceivable that the washing operation may be carried out in accordance with the present invention by providing a single annular or ring type of nozzle which will extend entirely'around the axis of the receptacle HI so as to discharge a substantially annular sheet of water at high pressure against the surface of the material as it flows outwardly along the perforate side wall of the receptacle H].

For the purpose of collecting the filtrate and wash water discharged by centrifugal force from the centrifugally operating receptacle Ill there is an annular housing 59 having an outer cylindrical wall 5| that extends upwardly to a point adjacent the upper end of the receptacle If). This housing 59 also has a conical inner wall 52 that extends inwardly toward the bottom of the receptacle l9. Extending upwardly between the side walls 5| and 52 there is an inner annular partition 53 which divides the housing 50 into two annular compartments. The partition 53 extends upwardly to a point substantially midway along the perforate side .of the receptacle In Where it will intercept-the molasses and/or other filtrate thrown out by centrifugal force from the receptacle l and at the same. time permit the wash water and/or-diluted filtrate to escape over the top thereof. With this arrangement it will be seen that the annular partition 53 divides the housing 50 into what may properly be termed two annular receptacles, the inner one of which is adapted to collect the raw filtrate and the outer one of which is adapted to collect the wash water and/or diluted filtrate. Attached to the bottom of the housing 59 and leading from the inner annular chamber, there is a conduit 54 by means of which the filtrate may be conducted to a subsequent station for a future treatment, and leading from the outer annular chamber there is a similar conduit 55 by means of which the wash water and/or diluted filtrate may be conducted to any suitable point.

For the purpose of collecting the filtered solids discharged over the rim of the centrifugally operating receptacle ID, as is also more clearly shown in Figure 2, there is an outwardly disposed stationary overhanging shroud-like enclo-' sure means 56. This shroud 55 is shown as supported upon the foundation fioor 42 by means of brackets or pedestals 51 that are arranged in spaced relation therearound. Rotatably mounted within the shroud 56 there is an annular platform 58 upon which the filtered solids are adapted to be deposited by the shroud 56 as they are discharged by centrifugal force from the receptacle H]. The annular platform 58 has an inner vertically extending wall 59 which extends upwardly to a point corresponding to the inside wall of the annular chamber 50. The annular platform 58 is shown as carried by a supporting ring 60 to which there is attached a large annular gear rack 61 with which a pinion 62 driven by a motor 63 is adapted to mesh. Thering gear 6| is supported upon' roller bearings 64 arranged in spaced relation in a circle' therebelow so that when the motor 63 is energized it will operate to drive the platform 58 at a suitable speed around the axis of the receptacle l9. As the platform 58 is'thus rotated it will collect the discharged solids and carry them around to a point along its path of travel where a stationary plow or scoop-like member 65 will divert the solids from the platform 58 and outwardly through a discharge outlet 66 and into a suitable hopper or other form of receptacle 61.

Upon referring to Figure 3, it will be noted that the plow or scoop-like member 65 is pivotally mounted at its outer end upon a hinge-like support 68 arranged at one side of the discharge outlet 66 of the shroud 56. This plow or scooplike member 65 may be straight or curved as shown and when installed its inner free end will be pressed tightly against the inner Wall 59 of the platform 58 so as to dislodge all solids carried around by the platform 58 to this point.

Before continuing with the description of the invention as illustrated in the remaining figures of the drawings, it should be here pointed out that while the shaft II which carries the centrifugallreceptacle I0 is shown as mounted upon bearings 36 and 31 that move therewith and as having a pulley l4 also movable therewith, it is to be understood that this shaft Il may be mounted so as to move axially within stationary bearings and that the pulley l4 may also be mounted and held against axial movement by providing a splined connection between it and the shaft H which will permit the shaft I l to move axially therethrough as it is rotated by the motor l2.

Upon referring to Figure 4, it will be noted that the perforate outwardly flaring side wall of the centrifugal receptacle l0, except for its outwardly flaring characteristic, is not unlike prior art receptacles of the so-called'cylindrical type. In other words, the receptacle l0 comprises an outer portion 69 of relatively heavy construction in which there is provided closely spaced and staggered apertures 10 through' which the filtrate may pass, the apertures 10 being provided with an enlarged or counter-sunk inlet "H; The portion 69 is shown as frustoconical and as covered upon its inside surface with a metal screen 12 which may be of wire mesh or in the form of a finely perforated relatively thin sheet of metal. As a further filtering medium, where a relatively fine mesh surface is desired, the screen I2 may be covered with bolting cloth [3. These superimposed filtering media will provide any degree of fineness in the filter surface that may be desired. The outer frustoconical wall 69 provides for strength and the inner screen and bolting cloth provide the fineness'of mesh. As a mounting for the perforate side wall 69 of the centrifugal receptacle [9, the invention is shown as contemplating a spiderlike member having an inner annular portion 14 that is adapted to be firmly secured upon a flange or supporting member .15 secured to the upper end of the vertical shaft H. The inner annular portion 14 of the spider-like member carries a plurality of radially spaced outwardly flaring arms 16 that are connected together at their upper ends by'means of a ring 11. As a means for securing the frusto-conical side wall 69 of the receptacle [0 upon the spider-like member there is acentral clampinggplate .18 which when clamped upon the supporting. member will firmly hold the 'frusto-conical; side wall 69 thereerably positioned so that it' will form. a substantially cylindrical extension at the outer end of the frusto-conical filtering surface formed as above ,describedyj An important aspect of this ring, as contemplated by the invention, is that its axial dimension should preferably be substantially equal to the magnitude of the recipro cating movement imparted to the centrifugal receptacle I0 when in operation.

.As shown in Figure 6f0f. the drawings and in 7 order to expedite the impartation of rotary motion to the material to be treated, as it is introduced through the 'feed. conduitfiB, the clamping plate 18 is provided with radially arranged depressions or flutings 8L.

It is believed that the operation of, the present invention will be evident-from the above description of the apparatus and, therefore, it should only be necessary to add that the material to be filtered will be introduced .through the conduit 45 at a steady and regulated rate of flow. This can be accomplished by anysuitable means; for example, a float and/or pressure responsive controlling means may be disposed in the conduit 65 so as to maintain a predetermined head or flow of the more or less fluid material. As the material thus introduced through the conduit 45 enters the centrifugal receptacle I0.it willflow outwardly and into contact with the flaring perforate side wall thereof where the 'syrup and/or other liquid will be thrownroutwardlythrough the filtering elements l0, l2 and 13. At the same time the solids will move along-the filter surface As illustrated, it will be noted that the angle of outward flaring provided in the'perforate side wall of the receptacle i0 is shown as approximately 40 from a true cylinder.

This angle of flaring has been found to be particularly well suited to the filtration of concentrated sugar massecuite. At this point, however, it should be stated that the angle of; flaring from a true cylinder may vary to form 10 to Experiments indicate that the angle of flaring should not exceed 45 where a high rotative. speed is used. In other words, the angle of flaring is dependent upon the rotativespeed to be maintained in the receptacle l0. For. example, where the rotative speed is of a high order, the angle of flaring may be somewhat reduced. Another consideration which necessarily influences the angle of outward flaring in the perforate side wall of the receptacle I0 is in the frequency and magnitude of the vertical reciprocation of the receptacle III. For example, as the magnitude of the reciprocation increasea'theangle of outward flaring fromtthe cylindrical may be decreased,

whereasrwith a relatively small magnitude of reciprocating movement, the angle of outward flaring may be increased. In experiments so far made in connection with continuous filtration of sugar massecuite, it has been found that .the-rotative speed of the centrifugal receptacle [0 may range from 900 to 1750 R; P. M. It has been alsofound that the angle of flaring may vary approximately a from 20 to 45, whilether'nagnitu'de of axial movement imparted to the centrifugal receptacle l0 may vary from of an inch to one inch with a frequency varying from to 4000 reciprocations per minute. In this latter connection it appears that with an increase in the frequency of reciprocation of the receptacle ID, the angle of flaring of its perforate side wall may be decreased.

While I have in the above attempted to briefly set forth some of the principal operating characteristics of the apparatus, it is to be understood that the values given areinno way to be considered as controlling, for with different materials the nature thereofwill determine largely at what speed the receptacle I0 should be rotated and with what magnitude and frequency it should be reciprocated. Therefore, while I have, for the sake of cleamess and in order to disclose my invention so that the same can be readily understood, described and illustrated a specific device and. arrangement, I desire to have it understood that this invention is not limited to the specific means disclosed, but may be embodied in other ways that will suggest themselves to persons skilled in the art. It is believed that this invention is new and it is, desired to claim it so that all suchchanges as comewithin the scope of the appended claims areto be considered as part of this invention. 1

Having thus described my invention, what I claim and desire to secure by Letters'Patent is:

1. In a continuously operating centrifugal ma-. chine of the character described, the combination of a centrifugally operating receptacle having a conical outwardly flaring perforate side wall through which a filtrate may pass, means disposed centrally of said receptacle for introducing a solution containing solids for separation, a driving means for rotating said receptacle at an operative speed about a vertical axis, the degree of flaring in the side wall of said receptacle being so proportioned that the introduced solids of said solution will not slide thereover under the infiuence of centrifugal force alone, a second driving means operating independently of said first driving means for imparting a positive'upand down movement of uniform magnitude to said receptacle in a direction parallel to its axis and irrespective of its speed of rotation, whereby the solids introduced into said receptacle will be discharged therefrom at a uniform rate with a jogging movement while said receptacle is in rotation.

.2. In a continuouslyoperating centrifugal machine of the character described, the combination of a centrifugally operating receptacle having a conical outwardly flaring perforate side wall through which a filtrate may pass, means disposed centrally of said receptacle for introducing a solution containing solids for separation, a drivingmeans for rotating said receptacle about a vertical axis, the degree of flaring in the side wall of said receptacle being so proportioned that the introduced solids of said solution will not slide thereover under the influence of centrifugal force alone, a second driving means operating independently of said first driving means for imparting a positive up and down movement of uniform magnitude to said receptacle in a direction parallel to its axis irrespective of its speed of rotation, whereby the solids introduced into said receptacle will be jogged outwardly along the wall of said receptacle and be discharged therefrom while said receptacle is in rotation, a mechanical speed changing power transmission device between said second driving means and said receptacle for changing the frequency of the up and down movements of said receptacle while it is in rotation to thus control the rate of discharge of the solids therefrom, and means associated with said receptacle adapted to collect the filtrate discharged through the perforate side wall of said receptacle and also the solids discharged over the rim thereof.

3. In a continuously operating centrifugal machine of the character described, the combination of a centrifugally operating receptacle having an outwardly flaring perforate side wall through which a filtrate may pass, means disposed centrally of said receptacle for introducing a solution containing solids for separation, a driving means for rotating said receptacle at a uniform speed about a vertical axis, means for spraying said solution and solids with water during rotation of said receptacle, a second driving means operating independently of said first driving means for imparting a positive up and down reciprocating movement of uniform magnitude to said receptacle in a direction parallel to its axis of rotation, whereby the solids introduced into said receptacle will be caused to move outwardly along the Wall of said receptacle with a jogging movement and be discharged over the rim of said receptacle as it rotates, means associated with said second driving means for varying the frequency of the up and down movements of said receptacle to thus control the rate of movement of the solids along the wall thereof, separating means adapted to collect the filtrate and wash water discharged at different points along the perforate side wall of said receptacle as the solids move outwardly therealong, and means disposed outwardly at the rim of said receptacle adapted to collect the solids discharged from said receptacle.

4. In a continuously operating centrifuge of the character described in which a centrifugally operating receptacle is reciprocated axially to cause a jogging movement of the material to be filtered over a perforate wall of the receptacle, the combination of a receptacle forming member having an upwardly and outwardly flaring perforate filter surface, a driving means for rotating said receptacle at a centrifugally operative speed, a second driving means operating independently of said first driving means for imparting an axial reciprocating motion of uniform magnitude to said receptacle independently of its speed of rotation, whereby the solids introduced into said receptacle will be discharged therefrom with a jogging movement while said receptacle is in rotation, and a lip forming member carried by said receptacle providing a cylindrical continuation of the inner surface of said receptacle over which the solids are jogged by the up and down movements of said receptacle, the cylindrical continuation provided by said lip forming member having an axial dimension substantially equal to the magnitude of the reciprocatin movement, whereby the solids will be discharged from said'receptacle in a uniform manner.

5. In a continuously operating centrifugal machine of the character described, the combination of a centrifugally operating receptacle having a frusto-conical outwardly flaring perforate side wall through which a filtrate may pass, means disposed centrally of said receptacle for introducing a solution containing solids for separation, means for rotating said receptacle about a vertical axis, the degree of flaring in the side wall of said receptacle being so proportioned that the introduced material will not slide thereover under the influence of centrifugal force, means for imparting a positive reciprocating movement to said shaft and receptacle in a direction parallel to the axis of rotation, whereby the solids of the material introduced into said receptacle will be jogged outwardly along the Wall of said receptacle and be discharged therefrom while in rotation, and means for controlling said last means whereby the frequency of reciprocation of said shaft and receptacle may be varied while in rotation.

6. In a continuously operating centrifuge, the combination of a vertical shaft mounted for both axial and rotary movement, means for driving said shaft about its axis at a high rotative speed, a receptacle secured upon the upper end of said shaft and having a perforate filter forming side wall through which the liquid of a solids containing solution will pass under the influence of centrifugal force, means at the lower end of said shaft adapted to impart a positive reciprocating axial movement thereto while in rotation, and means for varying the frequency of said reciprocating axial movement during the operation and independently of the speed of the centrifuge.

7. In a continuously operating centrifugal machine of the character described, the combination of a vertically disposed shaft mounted for both axial and rotary movement, means for driving said shaft about its axis at a high rotative speed, a centrifugally operating separator receptacle carried by the upper end of said shaft adapted to receive a fluid mass having solids for separation, said receptacle having an outwardly flaring perforate filter forming side wall through which the fluids of said mass may pass under the influence of centrifugal force, a transversely disposed shaft having a crank forming portion disposed centrally below said vertical shaft, a pitman connected between the crank forming portion of said latter shaft and said vertical shaft, driving means for rotating said transversely disposed shaft, and means for changing the speed of rotation of said transversely disposed shaft, whereby the frequency of reciprocation of said vertically disposed shaft and centrifugally operating separator receptacle may be changed during the operation thereof.

ARTHUR E. SORENSON. 

